Flame extinguisher for stuffing boxes



Jan. 23, 1934. H. T. WHEELER 1,944,385

FLAME EXTINGUISHER FOR STUFFING BOXES Filed Nov. 7, 1930 eets Sheet l /8I INVENTOR. 13 4 .2

Jan. 23, 1934. H T. WHEELER 1,944,385

FLAME EXTINGUISHER FOR STUFFING BOXES Filed Nov 71 5930 3 Sheets-Sheet 239 33 .34 I 23 Igg 4 37 22 3 INVENTOR.

Jan. 23, 1934.. H. T. WHEELER FL1 \ME EXTINGUISHER FOR STUFFING BOXESFiled Nov. 7, 1930 5 Sheets-Sheet 15 IN VEN TOR.

Fatented Jan. 23, 1934 oarrso srxrss P T-stir FLAME EXTINGUISHER FORSTUFFING BOXES This invention relates to certain new and use fulimprovements in stufiing-box packing for high temperatures and refersparticularly to the power packings of gas engines, and its chief ad- 5vantage resides in its capability of extinguishing the flame whichexists during the propelling stroke, reducing the latter to a hotnon-burning gas before it comes in contact with the packmg.

A further advantage is that the moving element in contact with the flamecontains a means for extinguishing the flame by reducing its temperatureand a method of stopping axial movement of the flame along the rod.

Another advantage is a series of connected chambers equipped with fineheat absorbing screens which permit equal pressure on both sides of themoving element. a o

A still further advantage is the absence of any '20 springs on themoving element exposed to the high temperatures, the weight and positionof the moving element beingcontrolled by counterbalancing weights.

A still further and important advantage is the means used to removecarbon from the extinguisher without cessation of operation.

With the foregoing advantages in view, other objects and advantages ofconstruction will become apparent as the description proceeds,accompanied by the drawings, wherein:

Figure 1 is a cross-sectional view of a gas engine stuffing-boxextinguisher constructed ac-- cording to this invention.

Figure 2 is an elevation of the primary extinguishing screens.

Figure 3 is a perspective 'of a section of the moving member incrosssection.

Figure 4 is an elevation of the moving element in its housing.

Figure 5 is a plan view various cross-sections.

Figure 6 is a perspective view of the floating composite member and thecounter-balancing weights. V

Figure 7 is an elevation of the secondary extinguishing screens.

Referring now especially to Figure 1, the engine cylinder-head containsthe stufling-box chamber for the packing and the extinguisher assembly;the packing cage 3 is held in place by several threaded bolts 2, 2, andthe packing gland 4 adjusts the fibrous packings rings 8 around rod 7 bymeans of the nuts 6, 6 on the studs 5, 5. Between the packing cage 3 andthe bottom of the stufiing-box is the extinguisher asof the extinguisherin sembly; the primary screen compartment 16 contains the screens 15,the composite floating ring operates in a housing 14, and the secondaryscreen compartment 10 contains the screens 9. The extinguishercompartments have pressure- 0, tight ground joint faces, so that whenthe packing cage 3 is drawn down tightly by the bolts 2, 2, a gasketl'iprevents any pressure from leaking by and around the stuffing-box walls.

The usual form of firing cage, or power pack- 5 ing, is a series ofsectional jointed rings in a multiplicity of compartments, the leakagealong the rod from one compartment to another reducing the pressure bysteps and at the same time the flamefrom explosion is cooled by the suc-7o cessive expansions until the pressure in the last compartment .iszero. In the packing and extinguisher built according to this invention,the

flame of explosion is guided thru the passages. filled with line screensof heat-absorbing materials, so made and arranged that the flame isgradually cooled without expansion until it. is below the kindlingtemperature of the mixed gases. As each stratum of mixture attempts toignite the vmixture between adjacent screens, the 30 screens absorb theheat and so retard flame propagation. In passing thru a series ofscreens, flame propagation is prevented in any desired degree. By meansof this invention the flame is first cooled by an extinguisher made ofheatabsorbing materials and the packing joint is easily held by aspecial fibrous packing, it not being the purpose of this specificationto dwell on the latter.

A further dampening of flame propagation thru the screens and along theopen points of the screen assemblies is secured by the burned mixturesof preceding explosions remaining in the screen chambers, this mixturebeing composed of carbon oxides, nitrogen, and practically no freeoxygen. Referringnow especially to Figure 1 it may be observed, that asthe gasket 17 prevents passage of the flame and the pressurearound thestufling-box walls, the flame is restricted to propagation and passagealong the rod 7 and the rib of the compartment 16, being free to passinto screens 15, and alsoalong the rod and between the rib ofcompartment 14. Referring to Figure 2, that part of the gas and flameunder pressure, progresses outwardly thru screens 15 until restrained bythe outer wall of compartment 16 and is cooled by the screens thru whichit passes. That part of the flaming mixture which passes by the wall ofcompartment 14 may pass thru the moving screens 13, or attempt to passbetween the wearing rings 12 and the rod '7. To make apparent thepassage of the gas at this point, Figure 3 represents the screens 13riveted by pins 24 to the wearing ring 12, the fire section blocks 11,11, being of suitable materials to dampen and cool any flame that maypass under the Wearing ring 12. Housing strip 21 maintains alignment ofthe composite screens, wearing rings and fire blocks, and any gas thatpasses thru screens 13 may go thru the holes 25 and into the openchamber of compartment 14.

The compartment 14 houses the floating member of the extinguisher aswill be seen by reference to the elevational view of Figures 4 and 5.The weight of the floating composite member is counterbalanced byweights 35 and 36 to remove any downward weight on the rod '7. Thefloating member is composed of screens 13, the wearing sections 12, 26,2'7 and 28 and the series of fire blocks 11, 11, etc. The wearing ringjoints are cut on lines parallel to tangents at the rod surface at theopen points of the ring sections. The joints are stepped to assist inassembling, and to allow for wear. The joints of the upper section 28are out so that they overlap the joint faces of both adjacent sections26 and 2'7, thus transferring most of the weight of section 28 to theside sections 26 and 2'7, the latter sections in turn bearing on theflexible housing 21. The joint surfaces of the bottom section 12 arelapped inside the joint surfaces of sections 26 and 27, so that theweight of section 12 is transferred to the latter sections. Referringnow especially to Figure 6, the housing 21 is a flexible strip havinganchor brackets 23 and 34 attached to each end at the bottom opening.Housing 21 is perforated around its circumference 'over thescreens 13 topermit free passage of the gas outwardly from rod '7. Chain 33 isattached to counterweight 35, then passed upwardly over shive pulley4'7, passes over pulley 19 and downward over pulley 48 and aroundhousing 21, crossing the open end of the latter and is attached toanchor bracket 23. Chain 22 is attached to counterweight 36, passesupwardly over pulley 29, passes over shive pulley 18, and downward overpulley 31, around housing 21 and across the open end of the latter to beattached to anchor bracket 34. Pulleys 31 and 4'7 are rotatable on pin32: pulleys 18 and 19 are rotatable on pin 20, and pulleys 29 and 48 arerotatable on pin 30. Pins 20, 30 and 32 are securely attached to housing14.

Referring now especially to Figures 4 and 5: holes 37, 38, 39 and 40 aremade thru the wall of compartment 14 to bypass any pressure fromcompartment 16 thru and into compartment 10, thereby removing any sidepressure against the moving member, or composite ring which is composedof the screens 13, Wearing ring sections 12, 26, 2'7 and 28 and the fireblock sections, 11, 11, etc. Passages 37a, 38a, 39a and 40a connect therespective by-pass holes to the outer chamber of compartment 14, therebyassuring equilibrium of pressure in all of the screened passages andcompartments.

Figures 1, 4 and 5 plainly show a'system of injecting vapour producingliquids into the screen sections, the use of which will be explainedunder operation. Referring then especially to Figure 1, the pipe 43 isconnected to a source of liquid thru valve. 49 and extends thruthepacking cage 3, thru screens 19 and the wall of compartment 10, thenthru the wall of compartment 14 to enter the screens 15 in compartment16. A plan view of the location of this liquid carrying line is shownparticularly in Figure 5, and an end elevation in Figure 4 shows theseries of openings 41, 43, 44 and 46 which are used for the samepurpose.

In operation, as the explosive mixture is being compressed, the screensin compartments 16 and 10 and the moving screens 13 are filled with themixture owing to the open nature of all passages, and by means of theby-pass holes 3'7, 38, 39 and 40, as well as passages 41 and 42 whichact as bypasses. At the time of ignition, flame propagation proceedsalong the rod '7 and enters the ex tinguisher thru compartment 16,screens 15 and moving screen 13. The flame is gradually cooled by comingin contact with the successive parts and layers of the screens until thetemperature is reduced below the kindling point, or that point at whichburning will exist; a hot gaseous mixture is the result. As the sourceof the flame is in the cylinder, the flame cannot propagate thru all ofthe screens, and that part of the mixture close to the fibrous is notignited. The soft packing rings 8 make a very tight joint on the rod,preventing any pressure escape which would carry streams of flamingmixture along the rod by which the mixture could be ignited in all partsof the extinguisher; the flame is therefore confined to the extinguishercompartments. The flaming mixture is cooled below the kindlingtemperature and a hot gas comes in contact with the soft fibrous rings8.

A further feature of operation which makes the extinguisher veryefficient is that'after the first few explosions, burned gases are leftin the screen chambers and as the soft packing rings 8 prevent anycirculation of air or addition of fresh mixture during the scavengingstroke, the burned gases persist in the screens and dilute the freshmixture forced in on the compression stroke. This mixing of fresh gasesand burned, dilutes the gases below that point necessary for burning orex plosion, so that there is little or no flame propagation past thefirst screen layers. An effective amount of unburnable gas is thereforeat all times in front of the soft packing.

A still further feature of operation which distinguishes this inventionis the removal of carbon and foreign matters. In the usual metallic ringconstruction, lubrication of all moving parts during operation is anecessity: any operation Which would remove the lubricant from the rodwould permit cutting of the packing rings. The problem of removingcarbon always has been diflicult, not being possible during operation askerosene, gasoline or some light oil must be used to soak the carbonloose, therefore necessitating a shutdown and frequent dismantling ofthe packing to scrape the deposits. In this invention, however, theremoval of carbon is best done during operation, utilizing the highesttemperature of the explosion. Vapour producing liquids, such as water,carbon tetrachloride, etc., are injected thru the pipe 43, and as theycome in contact with the hot screens, penetrate the cracks inthe'c'arbon coatings. The vapour between the screen and the carbon isexpanded and contracted by the intermittent heating and cooling of thescreens, the carbon flakes are quickly pried loose and is blown out thruthe openings 41 and 42. Thus it is possible to maintain this type ofscreen extinguisher for long periods of operation, the only attentionbeing that applied externally and without stopping the machine oropening the packing.

As concerns the'operation of the extinguisher device when exposed to'intermittent" flashes of high temperature gases having no flameysuch assuperheated steam, the screens 1 can be arranged toreduce'thetemperature a desired amount i'n a given period of time, sothat lubrication can-be maintained in'the main 'packingwithoutcarbonization. And as further concerns the use of screens before -a softpacking in conditions that the expansion produces freezing of theelement in the packing, the relation of the surfaces of the screens maybe reversed so that they store heat during the compression stroke, andradiate during the expansion, thus providing warm gases for the packing.

A further application of this device has been discovered, that whenliquids, or a mixture of liquids and vapours, or vapours with gases areinjected into the compartments intermittently, that a lowering oftemperature occurs, the construction being altered to permit the deviceto function properly.

As may readily be seen the construction of the compartments and cages issuch that the respective parts may be removed for cleaning andrepairing.

It is believed that the operation and many advantages of this inventionwill be understood readily, also that the design may be alteredconsiderably to meet local conditions without departing from the spiritof the invention, which I do define under the following claims:

I claim: 7

1. In a stufling-box containing a rod exposed to high temperature gasesand vapours subjected to pressure, a plurality of L-shaped cups forminga series of compartments, an outer case containing packing which sealssaid rod, said cage bearing against said cups, a porous heat absorbingscreen structure positioned in each of said compartments of such aporosity that increase of pressure will cause said gases and vapours topenetrate said structures, said structures absorbing the heat from saidgases and lowering their temperature.

2. In a stufiing-box containing a rod intermittently exposed to hightemperature gases, a plurality of metallic wire screen structures housedwithin a series of cups held pressure tight against the bottom of saidstuffing-box by an outer cage having means to seal said rod, saidscreens absorbing heat from said gases during increase of pressure andrediating heat to said gases during decrease of said pressure.

3. At the bottom of a stufling-box member containing a rodintermittently exposed to high temperature gases and vapours, a primaryand a secondary compartment formed by cups held pressure tight againstsaid stuffing-box walls, a porous reticulated heat absorbing structurepositioned in said primary compartment thru which said gases and vapoursmust pass to enter the outer portions of said secondary compartment,absorption of heat during said passage reducing the temperature of saidgases and vapours to a desired degree.

4. In a stufling-box containing a rod intermittently exposed to mixturesof high temperature gases and vapours, having a series of cups heldpressure-tight against said stufling-box walls, a primary compartmenthaving means to reduce the temperature of any gases which penetratetherein, a secondary compartment formed by said cups with radial wallsbetween which is positioned a. composite movable member in close contactwith said rod and movable radially with said rod thereby deflecting saidgases away from the surfaceof said rod, that part of said'compositemember adjacent to thesourceof said gases being comprised of a porousheat absorbing structure thru which said gasesmay passafter beingdeflected to enter the outer portions of said secondary compartment, thetemperature of saidgasesbeingreduced to a desired degree by said'pass'agel v 5. In a stuffing-box containing a rod intermittently exposedto high temperature gases and vapours and having a series of cups heldpressure tight against said stufling-bo-x walls thereby forming a seriesof compartments, a primary compartment at the bottom of said box havingmeans to reduce the temperature of any gases which may pass thru it, asecondary compartment containing a composite movable member in closecontact with said rod and movable radially with said rod, said compositemember consisting of a porous annular ring adjacent to the source ofsaid gases, a segmental annular wearing ring and a trailing segmentalring of suitable material, said porous ring being a metallic screen wirestructure thru which said gases may pass outwardly to reduce theirtemperature when deflected by said wearing ring which is comprised of aplurality of tangential jointed segments, said trailing ring beingcomprised of a plurality of segments dovetailed to said wearing ringsegments, said composite member thus formed being housed by a flexiblestrip, the entire weight of the composite assembly being counterbalancedby weights attached tosaid flexible strip.

6. In a stufling-box containing a rod intermit tently exposed to hightemperature gases and vapours, a series of cups forming primary,secondary and succeeding compartments and held pressure tight in saidstufling-box by an outer cage containing means to seal said rod, saidprimary compartment having means to reduce the temperature of gaseswhich may pass thru it, said secondary compartment having means todeflect gases away from the surface of said rod coincident with means toreduce the temperature thereby, said succeeding compartment housing aheat-absorbing structure which absorbs heat from such gases as may passinto it from the primary and secondary compartments, said gases andvapours being cooled to a desired degree before coming in contact withthe sealing means in the outer cage.

'7. In a stufling-box member intermittently exposed to high temperaturegases and vapours, a plurality of interconnected compartments, meanstherein to reduce the temperature of any gases and vapours which maypass thru said compartments, a passage enclosed in the walls of saidcompartments, and opening inwardly into said compartments, the outer endof said passage being connected to a source of vapour producingmaterials.

8. In a stuffing-box member intermittently exposed to explosive carbondepositing gaseous mixtures of the character used in gas engines, aplurality of interconnected compartments, and means therein includingmetallic straining ma terial, to reduce the temperature of any gases andvapours which may pass thru them.

9. In a stuffing-box member held pressure tight in said box by an outercage having means to seal said rod against intermittent high temperatureliquids and vapours under pressure, a plurality of interconnectedcompartments having means to reduce the temperature of any of series ofcups forming chambers about said rod, a packing assembly adjustable tohold said cups in position, foraminous, porous, heat absorbent layers ofmaterial in said cups, said layers acting to absorb heat from saidgaseous mixtures to lower the temperature thereof and protect saidpacking assembly.

HARLEY T. WHEELER\

